A survey of 90Sr and 137Cs activity levels of retail foods in Japan

A comprehensive survey was conducted on 90Sr and 137Cs activity levels in retail foods purchased from retail markets all over Japan during the period 1989–1994, and the annual effective dose equivalent due to dietary ingestion was estimated. The concentrations of 90Sr and 137Cs in the food samples were determined using γ-ray spectrometry and the radiochemical method. The following were clarified by this study: (1) The 90Sr and 137Cs activity concentration levels were below 1 Bq kg-1 for almost all food samples except for the dried foods. (2) The activity concentration levels of 90Sr and 137Cs in foods of animal origin were different from those of plant origin. Generally, the former had higher 137Cs and lower 90Sr activity concentrations than the latter. (3) The mean and maximum values of the annual effective dose equivalent from a dietary intake of 90Sr and 137Cs by the consumption of retail foods were estimated to be as low as 1•3 and 4•1 μSv, respectively